The present invention relates to tools (such as grinding disks and saws) with abrasive particles containing abrading grains and to a method of manufacturing such grinding tools. More specifically, the present invention relates to tools wherein at least a portion of the abrading grains are diamonds.
The diamond is the hardest material in nature and has found widespread use as an active component of grinding disks. A comprehensive discussion of the use of diamonds in grinding tools may be found in Kirk-Othmer, Encyclopedia of Chemical Technology (2d Ed.), Vol. 1, pages 26, 28, 31-33, 37 and 38; and Vol. 4, pages 293 and 301. As shown therein, the bonding agent for the diamonds can be a resin (resin bonded wheels) or metal (metal bonded wheels).
In addition to the conventional resin and metal bonded wheels, it has been found advantageous to prepare resin bonded wheels with the individual diamonds having a metal coating. Resin bonded diamond grinding wheels with metal coated diamonds show better durability than wheels with uncoated diamonds. This is apparently due, in part, to the fact that the thermal stresses at the interface between the metal coated diamond and the resin phase are decreased. In addition, uncoated diamonds tend to crack after prolonged grinding and come loose from the disk. The metal coating, on the other hand, retains the diamond splinters so that more of the diamond is utilized for grinding work than would otherwise be possible with uncoated diamonds.